Zinc-lathe.



No. 874,436. ATENTEDDEG. 24, 1907'. R. s. BR0WNE.

ZINC LATER. APPLIUATIQN lFILED JULY a, 1901.

A INVENTOR HSB rowne.

RALPH STUART BROWNE, OF ALAMEDA, CALIFORNIA.

ZINC-LATHE.

Specification of Letters Patent.

Patented Dec.l24=, 1907.

Application filed July 3. 1907- Serial No. 381,998.

To all whom it may concern.' i Be it known that I, RALPH STUART BRowNE, a citizen of the United States, and a resident of the city of Alameda, county of Alameda, State of California, have made certain new and usefulImprovements in Zinc- Lathes, of which I declare the following to be such a full and clear description as will enable those skilled in the art to construct and use the same.

Thisinvention relates to that type of lathe 'used for the purpose of cutting sheet zinc into shavinffs for the precipitation of gold from cyanid hsolutions of the same. The common way of producing these shavings is to roll a long sheet of zinc tightly around a cylinder or mandrel, the zinc is then secured so the cylinder will turn it with it, the cylinder, by suitable means and a tool is then caused to traverse the roll of zinc till the same has been entirely out from the cylinder.

The difliculty with the c`ommon type of machine is that the roll of zinc, which is from one to two inches thick, cannot' be entirely cut loose from the mandrel, and as the pre-l cise thickness of the cut cannot be regulated in cutting through sheets of material there are always a number of ragged edges on the roll of zinc which catch the shavings and cause them to roll tightly around the mandrel and roll of zinc. Another disadvanta e of this form of lathe is that the tool is liab e to penetrate too deep into the roll and out the mandrel, or if it is regulated so that it will not out the roll it will waste a considerable amount of zinc with each sup ly of the same. The reason for these troubles lies in the fact that there is always a certain amount of lost motion which cannot be entirely taken up, and no matter how small the lost motion the tool will cut too deep or too shallow. The rough edges of the zinc after it has been cut also cause a great deal of trouble ben cause of the whirling around of the shavings with the roll of zinc. Because of these difliculties with the common form of machine for cutting shavings it is necessary to have a man in constant attendance on the machine to see that the machine does not vget choked up so badly that it will not run at all. In the lathe which I have invented and desire to secure byLetters Patent of the United States these difficulties .are overcome'in the following ways: A slot is out in the mandrel on which the zinc is .to be rolled parallel to the axis of the same. A sheet of zinc is then made into a roll as shown in the drawings and the roll is loosely secured to the mandrel, the edges of the roll of zinc being soldered together. The long sheet of zinc to be made into shavings is then soldered to the loose cylinder of zinc on the mandrel and it is then rolled around the same till it makes a cylinder about an inch or more thick, its end is then soldered to the main art of the cylinder and the machine is rea y to go to work. N ow this cylinder of zinc has two possible motions, one of rotation due to the turnin of the mandrel, and the other of translation ue to the fact that it is loose on the mandrel and has a tongue projecting into the slot in the mandrel. A movable collar on the mandrel is then caused to move along thesame by `means of a sliding arm an anti-friction wheel preventing an undue loss of ower. When the machine is running the cdllar moves the zinc along the mandrel and as the mandrel rotates at a high rate of speed the zinc is-cut into ne shavings as it comes in contact with a iixedcuttin tool.

A lathe of t 's description requires no attention from an attendant other than to preparethe zinc and start the lathe, and there is no trouble with the zinc whirling around the mandrel for the reason that the shavings are all cut at one place and it is possible to cut away the bed of the machine so that all the shavings will fall to the oor as soon as they are cut, a suitable receptacle being provided for them to drop into. It is also necessary to'provide some means to stop the machine when the zinc is all cut oli the mandrel. This is done by means of a trigger which the moving arm comes in contact with,a this trigger when moved drops an arm which rises and throws the pawl of the feed wheel off and thus stops the feed of the collar across the mandrel.

In the drawings, in which like numerals of reference are applied to like parts throng out, Figure 1 is a plan of the athe,show1ng the opening in the bed to the floor, Fig. 2 is an end view of the large shaft and feed pawl,

Fig. 3 is an end view of the large-mandrel,

with several turns of zinc on it, Fig. 4 is a front elevation of the lathe, showing it in the position to b'egin cuttinga roll of Zinc, Fi 5 1s an end view of the Erst roll of zincapp 'ed to the lathe.

The base 1 of the lathe may be of any suittable' material or shape, such as common lathes have, except that it has a clear open- Y tending arm 28 of the extension coming ing, as shown in Fig. 1, to the floor. To this base 1 are attached to bearing posts 2, 3 for the main shaft 6, the bearing posts 4, 5 for the'feed screw, the tool post 15, the rest rail 13, and the throw-out lever 22.

The shaft 6 carries the mandrel 7, which has a slot 8 cut in its surface for its entire length. Carried by the mandrel is the large collar 9 which is free to slide along the mandrel 7. This collar 9 is moved along the mandrel 7 by means of the feed arm 11 attached to the threaded block 10 on the feed screw 14. In order that there may be as little friction aspossible between the feed arm 11 and the collar 9 ,the feed arm is provided with a small roller 12 which contacts with the collar and moves the same over the mandrel. Since the pressure of the roller against the collar is considerable, and since the mandrel moves down on the front side, there is a considerable thrust on the arm 11 downwardly, and this thrust is taken up by the restv rail 13, which holds the arm 11 in its proper place.

The main shaft is driven from a pulley 18 on the shaft 6, the opposite end of said shaft carrying an adjustab e pawl 19, held in place by the bolt, said bolt also providing means to adjust the throw of the pawl in a well known way in the slot in the end ofthe shaft. This pawl 19 contacts with the ratchet wheel 21 and drives it forward, thus moving the block 10 across the bed of the machine.

It will be observed that since the tool is stationary that it is necessary to provide some means for sto ping the feed of the ma chine before the co ar 9 has been pushed up to the cutting-tool. This means is the arm 22, which is provided with an extension 26, held in its position on the bed of the lathe by means of the two straps 27, an upwardly ex- UP to a point in proximity to the pawl 19. At the opposite end of the lever 22, it is bent around to form the arm 23, which arm is carried by the point 25 of the trigger 24, which latter is pivoted on the rest rail 18. When the block 10 comes to the trigger 24 it drops the lever 22, and said lever is heavy enough to fall quickly and throw the pawl off hedratchet wheel, thus stopping the machine The tool 16 which'cuts the shavings is secured in the post 15 by means of a set screw 17, and it is placed as near as possible to the end ofthe mandrel 7. The tool extends well githin the circle ofthe mandrel, as shown in The operation ofthe machine is as follows: A sheet of zinc as 22l is bent hack on itself as at 23', a short strip being left at the end to revent the doubled over portion from ump- 111g out of the slot 8 in which it is p aced.

The strip is then coiled around the mandrel, as indicated in Fig. 3 and as also indicated in Ifig. 5, in which only the first strip of zinc is shown, and it is then soldered at the end of the strip entirely across the cylinder. This makes a loose fitting cylinder on the mandrel and it forms the base for a long sheet of Zinc to be secured to the mandrel, by being soldered to the first strip. VA number of short strips may be used up in this way, if necessary. The machine is now started, the lever 22 being placed on the end ofthe trigger, and the Zinc will be cut from the roll without further attention till the entire roll has been cut up, the block carrying the feed arm tripping the trigger when it has reached a point at which it is necessary to stop the feed. This adjustment can be made much better than the adjustment of the tool and the piece of zinc left over is very small.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, modifications within the scope of the claims being reserved, is as follows:

1. In a Zinc lathe, the combination of a bed, a revoluble work holding mandrel, a collar carried by and slidable on the mandrel,

a means adapted to move the collar along the mandrel, and a fixed cutting tool at the end of the mandrel.

2. In a Zinc. lathe, the combination of a bed, a revoluble work holding mandrel, a collar carried by and slidable on said mandrel, a feed arm adapted to move said collar along the mandrel, a rest rail under the feed arm, and a fixed cutting tool at the end of the mandrel.

3. In a zinc lathe, the combination of a bed', a revoluble work holding mandrel, a slidable collar carried by the mandrel, a feed arm extending from a threaded block toward the mandrel and in contact with the collar, a feed screw carrying said threaded block and arm, and means to drive the feed screw from the mandrel shaft.

4. In a zinc lathe, the combination of a bed, a revoluble work holding mandrel, a slidable collar carried by the mandrel, a feed arm extending from a threaded block and in contact with the collar, a feed screw on which said block is carried, a rest rail for saidY feed arm extending along the bed, and means to drive the feed screw from the mandrel shaft.

In testimony whereof I have hereunto set my hand inthe presence of two witnesses this 27th day of June A. D. 1907, at San Francisco, State of California.

RALPH STUART BROWNE.

Witnesses: I

C. l?. GRIFFIN, 'CHARLES FRANGEE. 

